Weekly Test 1st Feb 2019

Explanation
Lead acetate is commonly known as "sugar of lead" due to its sweet taste. It is a white crystalline solid that is highly toxic and has been historically used as a sweetener in food and beverages. However, its use in food products is now banned in many countries due to its harmful effects on health. The other options listed, lead carbonate, lead chromate, and lead monoxide, do not have the same sweet taste and are not commonly referred to as "sugar of lead."

Explanation
Lead poisoning is caused by the ingestion or inhalation of lead, which can occur when lead-containing objects are handled or consumed. Souvenir bullets are often kept as mementos or decorations, and they can pose a risk of lead poisoning if the lead in the bullet is released into the environment or if the bullet is handled or ingested. Therefore, souvenir bullets can be a cause of lead poisoning.

Explanation
Increased calcium levels in the body can promote lead storage. This is because calcium and lead ions have similar chemical properties and can compete for binding sites in the body. When calcium levels are high, the body may prioritize storing lead instead of excreting it. On the other hand, calcium deficiency can lead to the release of stored lead from bones and other tissues. This occurs because the body may mobilize calcium from these storage sites, which in turn can release lead into the bloodstream.

Explanation
Lead poisoning can result in increased levels of delta-ALA, coproporphyrin, and protoporphyrin IX. Delta-ALA is a precursor in the heme synthesis pathway, and lead poisoning can disrupt this pathway, causing an accumulation of delta-ALA. Coproporphyrin is a byproduct of heme synthesis, and increased levels can indicate a disruption in this process due to lead poisoning. Protoporphyrin IX is the final product of heme synthesis, and elevated levels can also suggest a disturbance in heme production caused by lead poisoning.

Explanation
Lead poisoning occurs when there is an excessive amount of lead in the body. The body tries to eliminate this toxic substance through urine excretion. A urinary excretion level of >150 microgram/L indicates that the individual has a high concentration of lead in their body and is actively trying to eliminate it. This level is significantly higher than the other options provided, suggesting a more severe case of lead poisoning.

Explanation
The correct answer is an abrasion around the entry wound caused by a rifle. This is because an abrasion collar is a specific type of injury that occurs around a gunshot wound caused by a rifle. It is characterized by a ring of abraded or scraped skin around the entry wound, which is caused by the high velocity of the bullet and the resulting friction as it enters the body. This type of injury is commonly seen in forensic investigations to determine the type of weapon used in a shooting.

Explanation
When a bullet enters the body, it creates a high-pressure force that can cause back splatter. This refers to the blood and tissue that is forced out of the entry wound in the opposite direction of the bullet's trajectory. Singeing is another characteristic of an entry wound, which occurs when the bullet's heat causes the surrounding tissue to burn or char. The cherry red color of tissue is indicative of thermal injury caused by the bullet's heat. Lastly, an inverted margin refers to the edges of the entry wound being turned inward, which can suggest a bullet entry rather than an exit.

Explanation
An express bullet is a type of bullet designed for high velocity and long-range shooting. It is known for its flat trajectory and high accuracy. Piggyback bullets refer to a type of bullet that is attached to another bullet, often used for training or special purposes. Yawning bullet is not a recognized term in the context of bullets, and frangible bullets are designed to break apart upon impact to minimize the risk of over-penetration. Therefore, the correct answer is "Express bullet" as it does not fit into the category of bullet types mentioned in the question.

Explanation
Calcium carbamate is not a component of black gun powder. Black gun powder, also known as black powder, is composed of three main components: charcoal, potassium chlorate, and sulfur. These ingredients are mixed together in specific proportions to create the explosive powder. Calcium carbamate, on the other hand, is not commonly used in the production of black gun powder and does not contribute to its explosive properties.

Explanation
Choking of a gun refers to the constriction at the muzzle end. This means that the diameter of the barrel is reduced at the muzzle, which helps in increasing the accuracy of the projectile by providing a tighter and more controlled release of gases. This constriction helps in reducing the spread of the shot or bullet as it exits the barrel, resulting in a more focused and precise trajectory. Choking at the breech end or both muzzle and breech end is not correct as it does not accurately describe the concept of choking in a gun.